DESCRIPTION: Glaucoma is a leading cause of blindness world-wide and the second leading cause of blindness in the United States. About 80,000 of the 2,000,000 affected Americans are blind from glaucoma, and African Americans are at increased risk of developing the disease. It is estimated that as many as 50% of affected individuals do not realize that they have glaucoma. For many individuals, irreversible damage will have occurred by the time diagnosis and treatment have begun. Because treatments exist which can slow or stop progression of the disease, presymptomatic testing could potentially save sight in many individuals. Because the existing treatments don't work for everyone, improved treatment approaches are also needed. The PI long range goal is to identify genes responsible for adult onset forms of primary open angle glaucoma and to use cloned copies of those genes as tools with which to explore the underlying mechanisms of the disease, develop presymptomatic test(s), and design novel approaches to therapy and prevention. The approach of this project is to identify the location of glaucoma gene(s) on human chromosomes and to do mutation screening of candidate genes located at the site of mapped glaucoma genes. An initial collection of 56 families will be expanded, and sib pairs and isolate individuals will also be recruited. A genome scan will be carried out by screening DNA from family members with microsatellite repeat genetic markers from throughout the genome. Fine-scale mapping will be carried out in the immediate vicinity of the known glaucoma genes. Genes that have already been mapped to the region for which linage was detected will be evaluated for the presence of mutations in affected family members. Several specific candidate genes have been selected for use in mutation screening. Identification of new glaucoma genes will enhance our understanding of disease processes and assist in development of new diagnostic tests and alternative therapies.